Bonalumi is best known for his shaped vinyl-coated monochromatic canvases. Alongside Enrico Castellani and Dadamaino and Turi Simeti he further explored the physical possibilities of the classical canvas as an object. He created the term “extroflexions” invoking an intricate stretcher, which he would use to mold his canvases to create the illusion of an invisible force pushing out from underneath. Bonalumi referred to his works as Picture-Objects.

Bonalumi began his artistic journey in the 1950s, initially working as a self-taught artist before attending the Accademia di Brera in Milan. His early works were influenced by abstract expressionism and informel, but he soon became associated with the Spatialism movement, founded by Lucio Fontana. Spatialism aimed to explore the relationship between art, space, and time, emphasizing the use of unconventional materials and techniques to create a sense of depth and dimensionality. Bonalumi developed a unique approach to art-making by manipulating canvas and other materials to create three-dimensional reliefs and structures on the picture plane. He used elasticized canvas, wooden frames, and various types of paint to generate tension, curves, and protrusions, transforming the traditionally flat surface into a dynamic sculptural form. Through his innovative techniques, Bonalumi aimed to challenge the traditional boundaries of painting and engage the viewer in an immersive spatial experience.